Process and apparatus for separating a suspension bar from an electrode

ABSTRACT

Process and apparatus for separating a suspension bar (14) from an electrode (11) that is vertically suspended by this bar and that comprises, besides this bar, an electrolytic plate (12) and one or several suspension loops (13) fastened to the plate, the suspension bar extending through these loops. 
     The suspension bar (14) is first relieved of the weight of the plate (12) by bringing the electrode (11) in a horizontal position in which its plate (12) is caused to rest on a support (34 or 34&#39;). 
     The position of the bar (14) is then changed with regard to the position of the plate (12) by moving the support (34 or 34&#39;) with the plate (12) in a direction parallel to the longitudinal axis of the bar (14) while retaining the latter.

TECHNICAL FIELD

The present invention relates to a process for separating a suspensionbar from an electrode that is vertically suspended by this bar and thatcomprises, besides this bar, an electrolytic plate and one or severalsuspension loops fastened to the plate, the suspension bar extendingthrough these loops, according to which the suspension bar is firstrelieved of the weight of the plate by causing the latter to rest on asupport and then the position of the bar is changed with regard to theposition of the plate so as to separate the bar from the rest of theelectrode.

BACKGROUND ART

A similar process is described in U.S. Pat. No. 3,499,207. In this knownprocess, in order to relieve the suspension bar of the weight of theplate, the electrode is brought from the vertical position into aninclined position and it is kept in this position by causing the upperpart of the electrode, i.e. the suspension loops, the suspension bar andthe upper part of the electrolytic plate, to rest against an inclinedface of an upper support element and by causing the lower edge of theelectrolytic plate to rest on a lower supporting element. In order tochange afterwards the position of the bar with regard to the position ofthe plate, the bar is set moving by striking on one of its ends by meansof a striking device, mounted on one side of said inclined face and itis kept moving by means of an extracting roller mounted on the otherside of said inclined face. While moving the bar is supported by saidextracting roller and by several support rollers mounted on the inclinedface between the striking device and the extracting roller. When thesuspension bar is separated in this way from the rest of the electrode,the lower support is caused to turn and the electrode deprived of itssuspension bar falls on an evacuating conveyor.

In order that this known process leads to the expected result, namelythe separation of the bar from the rest of the electrode, it isnecessary that, when the electrode reaches said inclined position, thesuspension bar is engaged with the extracting roller and that it exposesone of its ends to the striking device. Now, it may happen that at thatmoment the suspension bar is not engaged with the extracting rollerand/or does not expose one of its ends to the striking device, forinstance, when the lower edge of the electrolytic plate, which rests onthe lower support element and which is supposed to be smooth, isdeformed by electrolytic incrustations, or when for any reason thesuspension loops of the electrode, which are supposed to have the samelength, have a substantially different length, or even when for anyreason the height of the electrolytic plate, which is supposed to bealways the same, differs substantially from the normal height. Hence,this known process lacks reliability, since at the moment the suspensionbar is relieved of the weight of the plate, the position of thissuspension bar can vary substantially from one electrode to the other.

The aim of the present invention is to provide a process as definedbefore that avoids the drawback of the aforesaid known process.

SUMMARY OF THE INVENTION

According to the invention, in order to relieve the suspension bar ofthe weight of the plate, the electrode is brought from its verticalposition into a substantially horizontal position, in which its plate iscaused to rest on the support, and, while the electrode is brought tothe substantially horizontal position, it is kept suspended by itssuspension bar so that this bar occupies a predetermined position at themoment the plate is caused to rest on the support and the electrode ishence no longer suspended by its bar. In doing so, one can then changethe position of the bar with regard to the position of the plate in thebest conditions, whatever the state of the lower edge of the plate, thelength of the suspension loops and the height of the plate may be.

In order to change the position of the bar with regard to the positionof the plate, it is advantageous to retain the bar while moving thesupport with the plate parallelly to the longitudinal axis of the bar,which allows to form easily very stable piles with the electrodes, fromwhich the suspension bars were separated, as will be explained furtheron.

The bar is preferably retained by one of its ends while the support withthe plate is moved so as to cause the latter to pass before the otherend of the bar.

After having deposited the plate on the support and before moving thesupport with the plate, it is very useful to cause the suspension bar toturn a determined angle around its longitudinal axis. Should the baradhere to the suspension loops, it would in this way be loosened fromthese loops.

The present invention relates also to an apparatus for separating asuspension bar from an electrode that is vertically suspended by thisbar and that comprises, besides this bar, an electrolytic plate and oneor several suspension loops fastened to the plate, the suspension barextending through these loops, comprising

a support,

means for depositing the plate of the electrode on this support so as torelieve the suspension bar of the weight of the plate, and

means for changing the position of the bar with regard to the positionof the plate, when the latter has been deposited on the support, so asto separate the bar from the rest of the electrode.

Such apparatus is described in said patent U.S. Pat. No. 3,499,207. Thisknown apparatus does not allow to realize the afore defined process ofinvention.

The apparatus according to the invention that enables to realize thisprocess is characterized in that the means for depositing the plate ofthe electrode on the support are adapted to bring the electrode in asubstantially horizontal position and comprise means for sustaining thesuspension bar of the electrode so that this bar occupies apredetermined position at the moment the plate is deposited on thesupport.

BRIEF DESCRIPTION OF THE DRAWINGS

Other details and characteristics of the invention will appear from thedescription, given hereafter as a non-restrictive example and withreference to the enclosed drawings, of a process and apparatus forwashing and stacking cathodes, i.e. electrodes provided with asuspension bar, comprising an embodiment of the process and apparatusaccording to the invention, wherein:

FIG. 1 represents a schematic plan view of an installation for washingand stacking cathodes, comprising an apparatus according to theinvention for depriving the cathodes of their suspension bar after theirwashing and before their stacking.

FIG. 2 represents an enlarged vertical section through the installationof FIG. 1, made along line II--II of FIG. 1.

FIG. 3 represents an elevational lateral view of a device for conveyingcathodes in the installation of FIG. 1.

FIG. 4 represents a front view of the device of FIG. 3.

FIG. 5 represents an elevational lateral view of the washing station ofthe installation of FIG. 1.

FIG. 6 represents a transversal section through the washing station ofFIG. 5.

FIG. 7 represents a horizontal section through the washing station ofFIG. 6, made along line VII--VII of FIG. 6.

FIG. 8 represents an enlarged and detailed plan-view of a stackingpreparation station of the installation of FIG. 1.

FIG. 9 represents an elevational lateral view of the stackingpreparation station of FIG. 8.

FIG. 10 represents a front view of the entry of the stacking preparationstation of FIG. 8.

FIG. 11 shows the unhooking of a cathode from the conveying device ofFIG. 3 in the stacking preparation station of FIG. 10.

FIG. 12 shows the depositing of an unhooked cathode in the stackingpreparation station of FIG. 10.

FIG. 13 represents an enlarged and detailed plan view of part of thestacking preparation station of FIG. 8, this part being a pivoting gripfor removing the suspension bars from the cathodes.

FIG. 14 represents a front view of part of the grip of FIG. 13 inloading position.

FIG. 15 represents a front view of the grip of FIG. 13 in unloadingposition.

FIG. 16 shows the way in which the cathodes are stacked near the outletof the stacking preparation station of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The same reference notations indicate identical elements in thedifferent figures.

The installation represented on FIG. 1 comprises an endless monorail 1,provided with a number of carriages 2 that are individually driven andcontrolled. Monorail 1 serves successively:

a loading station 3, in which a pair of cathodes to be washed aresuspended to the carriages 2,

a washing station 4, in which the cathodes suspended to carriages 2 arewashed by sprinkling,

a first stacking preparation station 5, in which the washed cathodes areremoved from carriages 2, deposited on a conveyor, deprived of theirsuspension bar and turned, and

a second stacking preparation station 6, which starts operating when thefirst station 5 has a breakdown.

Cathodes prepared for stacking in station 5 are stacked in 7 and 7' andthe piles that are formed are carried off in 8 and 8'. Cathodes preparedfor stacking in station 6 are stacked in 9 and 9' and the piles that areformed are carried off in 10 and 10'.

As shown on FIG. 3, a cathode 11 consists of a metal plate 12 providedwith two suspension loops 13 through which extends a suspension bar 14.

Loading station 3, shown on FIG. 2, comprises two pairs of conveyingchains 15 and 16 provided with a non-represented motor driving thechains step by step in the direction indicated by arrows 17 and 18'.Cathodes 11 to be washed coming from the tankhouse are deposited ingroups by racks 19 and 20 on the pairs of chains 15 and 16, which bringcathodes 11 to the walking beam transfer devices 21 and 22. The latterlift cathodes 11 one by one from chains 15 and 16 and suspend them onthe hooks 23 of a carriage 2 (see FIGS. 3 and 4), which brings them towashing station 4.

As shown on FIGS. 5 and 7, washing station 4 comprises a washingcompartment 24 and a rinsing compartment 25. These compartments 24 and25 are equipped with a series of sprayers 26 arranged so as to sprinkleboth faces of the cathodes 11 that are brought into these compartmentsby carriage 2 (see also FIG. 6). Sprayers 26 of rinsing compartment 25are connected with a hot water source. The rinsing water produced inrinsing compartment 25 is collected in tank 27, from where it overflowsin 28 to reach via syphon 29 tank 30, which is connected through anon-represented pump with sprayers 26 of washing compartment 24 andwhich collects the wash water produced in this compartment. Tank 30 isprovided with a weir 31 and the wash water that overflows at 31 isdrained off to a neutralization installation. The tightness ofcompartments 24 and 25 is ensured by pairs of flexible V-shaped elements32 and 33 (FIGS. 6 and 7).

As shown on FIGS. 8 to 10, stacking preparation station 5 comprises:

two pairs of conveying chains 34 and 34',

an unhooking device 35 for removing a pair of washed cathodes 11 from acarriage 2 and for depositing them horizontally, one on the pair ofchains 34 and the other on the pair of chains 34',

two grips 36 and 36' for depriving cathodes 11 deposited on chains 34and 34' of their suspension rod 14,

two devices 37 and 37' for carrying off the suspension bars 14 recoveredin 36 and 36', and

two turning tables 38 and 38' for lifting cathodes 11 deprived of theirsuspension bar 14 from chains 34 and 34' and for causing them to turn.

Unhooking device 35 comprises a first pair of arms 39 fastened to ashaft 40 and a second pair of arms 39' fastened to a shaft 40'. Shafts40 and 40' are mounted in bearings 41 and 42, parallelly to thelongitudinal axis of suspension bar 14 of cathodes 11 that are broughtin station 5 by a carriage 2. Shaft 40 is fastened to a toothed wheel 43and shaft 40 to a toothed wheel 44 that is in mesh with toothed wheel43. Toothed wheel 43 is connected with a lever 45 driven by cylinders 46and 47. Hence, the moving of lever 45 brings about the moving inopposite direction of pairs of arms 39 and 39' along arrows 48 and 48'(see FIG. 10). When rod 49 of cylinder 46 is completely out and rod 50of cylinder 47 is completely in, pairs of arms 39 and 39' are ininclined waiting positions P1 and P1'. When both rods 49 and 50 arecompletely in, pairs of arms 39 and 39' are in vertical cathode grippingpositions P2 and P2'. When both rods 49 and 50 are completely out, thepairs of arms are in horizontal depositing positions P3 and P3'.

Each arm 39 and 39' is provided with a working arm 51, equipped with alifting hook 52 and three supporting hooks 53 (see FIG. 11). Thisworking arm 51 is connected with its carrier arm 39 or 39' by twojointed couplings 54 and 55 and by a cylinder 56 that brings the workingarm 51 in working position P4, when its rod 57 is pushed out, and backin waiting position P5 when its rod is moved in.

As shown on FIGS. 13 to 15, grip 36' comprises a fixed jaw 58 and amobile jaw 59, connected with fixed jaw 58 by pivot 60 and driven bycylinder 61. Fixed jaw 58, mobile jaw 59 and cylinder 61 are mountedtogether on a shaft 62 that is mounted in a bearing 63 and fastened to alever 64. Lever 64 is driven by cylinder 65. When rod 66 of cylinder 61is completely in, grip 36' is open (FIG. 14) and when it is completelyout, grip 36' is closed (FIGS. 13 and 15). When rod 67 of cylinder 65 iscompletely in, grip 36' is in unloading position (FIG. 15) and when itis completely out, grip 36' is in loading position (FIGS. 13 and 14). Itis obvious that grip 36 is the reflected image of grip 36'.

Device 37' for evacuating the suspension bars recovered in 36' comprisesa vertical conveyor 68 provided with hooks 69 and an horizontal conveyor70 leading to a central conveyor 71 (see FIGS. 10 and 15). Device 37 isthe reflected image of device 37'.

Pairs of conveying chains 34 and 34' are mounted on frames 72 and 72'(see FIGS. 8, 10 and 12) and driven by motors 73 and 73' causing them tomove foreward step by step, parallelly to the longitudinal axis ofsuspension bar 14 of cathodes 11 that are brought in station 5 by acarriage 2.

The various parts of stacking preparation station 5, which have beendescribed herebefore, are mounted on a frame 74 (see FIGS. 8, 9 and 10).

The installation of FIG. 1 comprises moreover known but not representeddetection devices for detecting the arrival of an empty carriage 2 atloading station 3 and the arrival of a loaded carriage 2 at washingcompartment 24, at rinsing compartment 25, at the first stackingpreparation station 5 and at the second stacking preparation station 6;the detection device of the latter station starts operating only whenfirst station 5 has a breakdown. When a carriage 2 is detected by one ofthese detection devices, its motor 75 (see FIG. 2) stops for apredetermined time T, for instance for 5 seconds.

The apparatus operates as follows. When an empty carriage 2 is detectedat loading station 3, it stops and transfer devices 21 and 22 startoperating and suspend a pair of cathodes 11 to carriage 2. After a timeT, the loaded carriage 2 leaves loading station 3 and goes to washingstation 4. When the loaded carriage 2 is detected at washing compartment24, it stops and sprayers 26 of this compartment start operating. Aftera time T, sprayers 26 stop operating and carriage 2 passes to rinsingcompartment 25. When carriage 2 is detected at rinsing compartment 25,it stops and sprayers 26 of this compartment start operating. After atime T, sprayers 26 of rinsing compartment 25 stop operating andcarriage 2 passes to stacking preparation station 5. When carriage 2 isdetected at station 5, above unhooking device 35 that is at that momentin waiting position P1--P1', carriage 2 stops and rod 49 of cylinder 46is moved in, thereby bringing pairs of arms 39 and 39' in their grippingposition P2 and P2'. When pairs of arms 39 and 39' are detected inpositions P2 and P2' by a known and not represented detecting device,rods 57 of cylinders 56 are pushed out, thereby bringing working arms 51from their waiting position P5 to their working position P4, in whichthey lift the cathodes 11 from carriage 2 (see FIG. 11). Now, rod 49 ofcylinder 46 and rod 50 of cylinder 47 are pushed out, thereby bringingpairs of arms 39 and 39' that each carry a cathode 11, from theirgripping position P2--P2' to their depositing position P3--P3', in whichplate 12 of the cathode 11 carried by pair of arms 39 is deposited onchains 34 and one end of the suspension bar 14 of this cathode on thefixed jaw of grip 36 and in which plate 12 of the cathode 11 carried bypair of arms 39' is deposited on chains 34' and one end of thesuspension bar 14 of this cathode on the fixed jaw 58 of grip 36' (seeFIGS. 12 and 14). During the passage of arms 39 and 39' from positionsP2--P2' to positions P3--P3', cathodes 11 remain suspended by theirsuspension bar 14 on hooks 52 while their plates 12 rest on hooks 53until plates 12 are deposited on chains 34--34' (see FIG. 12). Sincecathodes 11 are kept suspended by their suspension bar 14 until themoment they are deposited, this suspension bar occupies always the sameposition at said moment; in that position bar 14 is, in the presentcase, oriented as it was at the moment cathode 11 was still verticallysuspended at at carriage 2 in station 5. When pairs of arms 39 and 39'are detected in positions P3 and P3' by a known and not representeddetecting device, rods 57 of cylinders 56 are moved in, thereby bringingworking arms 51 back in their waiting position P5 and then rod 50 ofcylinder 47 is moved in, thereby bringing pairs of arms 39 and 39' backin their waiting position P1--P1'. The detection of pairs of arms 39 and39' in P3 and P3' starts also the clamping of suspension bars 14 ofcathodes 11 by grips 36 and 36': rods 66 of cylinders 61 are pushed outand grips 36 and 36' are closing. When the closing of grips 36 and 36'is detected by a known and not represented detection device, rods 67 ofcylinders 65 are moved in and grips 36 and 36' pass from their loadingposition (FIGS. 13 and 14) in their unloading position (FIG. 15).Suspension bars 14 are thus turned 90° around their longitudinal axis,thereby loosening them from suspension loops 13 in case they shouldadhere to these loops. When grips 36 and 36' are detected in theirunloading position, motors 73 and 73' of conveying chains 34 and 34'bring cathodes 11 above turning tables 38 and 38'. Cathodes 11 are inthis way deprived of their suspension bars, which are clamped in 36 and36'. When cathodes 11 are detected above turning tables 38 and 38', rods66 of cylinders 61 are moved in, grips 36 and 36' open and suspensionbars 14 fall on a hook 69 of the vertical conveyors 68 of devices 37 and37', which convey bars 14 via central conveyor 71 to an apparatus forproducing starting cathodes. Then rods 67 of cylinders 65 are pushed outand grips 36 and 36' are brought back to their loading position (FIG.14).

At the detection of cathodes 11 above turning tables 38 and 38', chains34 and 34' stop and tables 38 and 38' lift the cathodes 11 and turn them90° alternately clockwise and anticlockwise. Cathodes 11 are then liftedfrom tables 38 and 38' by means of a known and not represented deviceand stacked respectively in 7 and 7'. Very stable piles are obtained asshown on FIG. 16.

The loaded carriage 2 that had stopped in station 5 has started againunloaded after a time T to pass again to loading station 3.

Hereinbefore a description was given of the washing and stacking ofsymmetrical cathodes, i.e. cathodes, the suspension bar of which has anidentical section over its whole length. It is known that inelectrolysis also asymmetrical cathodes are used, i.e. cathodes with asuspension bar, one end of which is twisted 90° with regard to the restof the bar and that these cathodes are then used in groups of leftcathodes and in groups of right cathodes, a left cathode having thetwisted end of its suspension bar at the left side of its electrolyticplate and a right cathode having the twisted end of its suspension barat the right side of its electrolytic plate. It is clear that a leftcathode can be converted into a right cathode, for instance by causingit to turn 180° around its vertical axis and vice versa. If asymmetricalcathodes have to be treated in the before described installation, oneshall take care that the twisted end of the suspension bars shall beclamped by grip 36 or 36'. Hence, the installation shown at FIG. 9 issuitable to treat right cathodes, grip 36 being located at the rightside of the deposited cathode (see FIG. 8). In order that abovedescribed installation is able to treat asymmetrical cathodes, the leftcathode groups should previously be converted into right groups. It isalso possible, however, to adapt the installation of FIG. 9 in such away that it can treat both left cathodes and right cathodes. To thisend, one can mount a second grip at the left side of the depositedcathode, extend pair of chains 34 to the right, modify the drivingsystem of these chains so as to enable them to move also to the rightand install also a turning table 38 on the right wing of pair of chains34. The right grip 36 and the left grip have to be mounted so that theycan be brought from a rest position remote from chains 34 into a workposition near to chains 34 and vice versa. The left grip and the rightwing of pair of chains 34 are then used for treating a left group ofcathodes and the right grip 36 and left wing of pair of chains 34 fortreating a right group of cathodes.

It should be understood that the afore described installation can bemodified in many other ways without interfering with its essence.

So, for instance, second stacking preparation station 6 may be omitted,but this modification decreases of course the flexibility of theinstallation.

The installation can be easily adapted to treat cathode per cathodeinstead of two cathodes at a time. This modification decreases sensiblythe investment costs, but also the productiveness of the installation.

Instead of providing washing station 4 with a separated washing 24 andrinsing compartment 25, one single compartment can be used for washingand rinsing, provided that this single compartment is equipped withwashing and rinsing sprayers or with sprayers adapted to sprinklealternately a washing and rinsing liquid.

Monorail 1 and carriages 2 may be replaced by a conveying chain providedwith hooks, but this modification reduces seriously the flexibility ofthe installation.

Pivoting grips 36 and 36' may be replaced by fixed grips, if thesuspension bars of the cathodes to be treated have but little or notendency to adhere to the suspension loops of these cathodes.

Chains 34 and 34' may be provided with cams in order to facilitate theconveying of cathodes 11 by these chains.

It is obvious that the afore described installation can be easilyconverted into an installation for washing and stacking anode scrap,anodes being electrodes consisting of a metal plate provided with twosuspension lugs. Therefor it is enough to omit grips 36 and 36', sincethe anodes have no suspension bar.

We claim:
 1. In an electrode comprising an electrolytic plate having oneor more suspension loops attached to the plate and a suspension barextending through the loops for vertical support of the plate, a methodfor separating the bar from the loops of the plate which comprisesmoving the plate from a vertical position to a substantially horizontalposition; positioning the plate on support means thereby relieving theweight of the plate on the bar; and removing the bar from the loops ofthe plate while the plate is in contact with the support means.
 2. Themethod according to claim 1 wherein the bar is removed from thesuspension loops of the plate by retaining the bar in a fixed positionwith respect to the position of the loops of the plate when the plate isinitially positioned on the support means and thereafter moving thesupport means and plate in a direction parallel to the longitudinal axisof the bar.
 3. The method according to claim 2 wherein the bar isretained in the fixed position by fixing one end of the bar before thesupport and plate are moved.
 4. The method according to claim 2 whichfurther comprises rotating the bar through a predetermined angle aroundits longitudinal axis after the plate has been placed on the supportmeans and before the support means and plate are moved.
 5. The methodaccording to claim 4 wherein the predetermined angle is about 90°.
 6. Inan electrode comprising an electrolytic plate having one or moresuspension loops attached to the plate and a suspension bar extendingthrough the loops for vertical suspension of the plate, a process forseparating the bar from the loops of the plate which comprises: movingthe plate from a vertical position to a substantially horizontalposition; positioning the plate on support means thereby relieving theweight of the plate on the bar; rotating the bar through a predeterminedangle around its longitudinal axis; and removing the bar from the loopsof the plate by holding one end of the bar to retain the bar in a fixedposition and thereafter moving the support means and plate in adirection parallel to the longitudinal axis of the bar.
 7. In anelectrode comprising an electrolytic plate having one or more suspensionloops attached to the plate and a suspension bar having an longitudinalaxis extending through the loops for vertical support of the plate, anapparatus for separating the bar from the loops of the plate comprisingmeans for moving the plate from a vertical position to a substantiallyhorizontal position; means operatively associated with the moving meansfor supporting the plate in the horizontal position to relieve theweight of the plate on the bar; and means operatively associated withthe support means for removing the bar from the loops of the plate whilethe plate is in contact with the support means.
 8. The apparatusaccording to claim 7 wherein the means for removing the bar from theloops of the plate comprises means for retaining the bar in a fixedposition with respect to the position of the loops of the plate when theplate is initially positioned on the support means and means operativelyassociated with the retaining means for moving the support means andplate in a direction parallel to the longitudinal axis of the bar. 9.The apparatus according to claim 8 wherein the means for retaining thebar comprises gripping means.
 10. An apparatus according to claim 7further comprising means operatively associated with the support meansfor rotating the bar through a predetermined angle around itslongitudinal axis while the plate is in contact with the support meansand before the bar is removed from the loops of the plate.
 11. In anelectrode comprising an electrolytic plate having one or more suspensionloops attached to the plate and a suspension bar having a longitudinalaxis extending through the loops for vertical support of the plate, anapparatus for separating the bar from the loops of the plate comprisingmeans for moving the plate from a vertical position to a substantiallyhorizontal position; means operatively associated with the moving meansfor supporting the plate in the horizontal position to relieve theweight of the plate on the bar; means for removing the bar from theloops of the plate while the plate is in contact with the support means,the removing means comprising means for gripping one end of the bar toretain the bar in a fixed position with respect to the position of theloops of the plate when the plate is initially positioned on the supportmeans and means for moving the support means and plate in a directionparallel to the longitudinal axis of the bar; and means operativelyassociated with the gripping means for rotating the bar through apredetermined angle around its longitudinal axis while the plate is incontact with the support means but before the support means and plateare moved.
 12. The apparatus according to claim 11 wherein the supportmeans comprises the upper run of an endless conveyer which movesparallel to the longitudinal axis of the bar.
 13. The apparatusaccording to claim 11 wherein the means for moving the plate from avertical position to a substantially horizontal position comprises ashaft mounted on bearings parallel to the longitudinal axis of thesuspension bar in its initial position; a pair of supporting armsconnected to the shaft; drive means for rotating the shaft and movingthe supporting arms from an inclined waiting position to a verticalposition for gripping the electrode and from the vertical positionthrough the inclined waiting position to a horizontal depositingposition and further from this horizontal position back to the inclinedwaiting position; a working arm for each supporting arm, each workingarm comprising an electrode lifting hook and at least one supportinghook for the plate, the working arm being connected to its respectivesupporting arm by jointed couplings; and drive means for moving theworking arms from a waiting position to a working position and back,said waiting and working positions being such that when the working armsmove from the waiting position to the working position, with the supportarms in the vertical gripping position, the lifting hooks lift theelectrode to be treated by the suspension bar, and, when the supportingarms pass from the vertical gripping position to the horizontaldepositing position with the working arms in the working position, thesuspension bar remains supported by the lifting hooks and the plate issupported by the supporting hooks.
 14. The apparatus according to claim11 wherein the means for gripping the bar comprises a grip having afixed jaw adapted to support one end of the bar and a mobile jaw adaptedto exert pressure on the same end of the bar, and wherein the means forrotating the bar comprises means for rotating the grip around thelongitudinal axis of the bar.
 15. In an electrode comprising anelectrolytic plate having one or more suspension loops attached to theplate and a suspension bar having a longitudinal axis extending throughthe loops for vertical support of the plate, an apparatus for separatingthe bar from the loops of the plate comprising: a shaft mounted onbearings parallel to the longitudinal axis of the suspension bar in itsinitial position; a pair of supporting arms connected to the shaft;drive means for rotating the shaft and moving the supporting arms froman inclined waiting position to a vertical position for gripping theelectrode and from the vertical position through the inclined waitingposition to a horizontal depositing position and further from thishorizontal position back to the inclined waiting position; a working armfor each supporting arm, each working arm comprising an electrodelifting hook and at least one supporting hook for the plate, the workingarm being connected to its respective supporting arm by jointedcouplings; and drive means for moving the working arms from a waitingposition to a working position and back, said waiting and workingpositions being such that when the working arms move from the waitingposition to the working position, with the support arms in the verticalgripping position, the lifting hooks lift the electrode to be treated bythe suspension bar, and, when the supporting arms pass from the verticalgripping position to the horizontal depositing position with the workingarms in the working position, the suspension bar remains supported bythe lifting hooks and the plate is supported by the supporting hooks; anendless conveyor which moves parallel to the longitudinal axis of thebar for supporting the plate in a horizontal position; means forremoving the bar from the loops of the plate while the plate is incontact with the endless conveyor, the removing means comprising a griphaving a fixed jaw adapted to support one end of the bar and a mobilejaw adapted to exert pressure on the same end of the bar to retain it inposition; means for moving the endless conveyor and plate in a directionparallel to the longitudinal axis of the bar; and means for rotating thebar through a predetermined angle while the plate is in contact with theendless conveyor but before the bar is removed from the loops of theplate, the rotating means comprising means for rotating the grip aroundthe longitudinal axis of the bar.